Lock nut



May 22, 1951 v R. c. sHERwooD ETAL 2,554,448'- Locx NUT Filed Oct. l, 1948 BERTRAND DELE/QA)l MOL/ROM ROBERT C. SHERWOOD,

INVENTORS.

HERZ/6 8 CALDWELL,

ATTORNEYS.

gr/MMM j.

HUEBNER,BEEHLER. WORREL.

Patented May 22, 1951 OFFICE LOCK NUT Robert C. Sherwood, West Hollywood, and Bertrand Deleray Mouton, San Marino,

Calif.

Application October 1, 1948, Serial No. 52,204

2 Claims. l

load tension is nevertheless maintained at a high value. It has simultaneously been possible to accommodate lock nuts to bolts of extremes of pitch diameter within any given size, whether these be of high or low manufacturers tolerance.

It is among the objects of this invention to provide a lock nut suitable for commercial bolts of extreme pitch diameter within yany given size.

j It is another object of the invention to provide a new and improved lock nut having an economical stamped shell and provision for added strength incorporated therein where needed but independently of the shell.

It is another object of this invention to provide in a lock nut of the desired @character described, means for pre-establishing the limits of constriction and/or relative axial movement of the boltengaging core regardless of added wrench torque.

Another object of this invention is to provide an improved keying means to prevent rotation but permit longitudinal movement of the operative parts.

Yet another object of the invention is to provide a core-constricting means independent of the shell and whose resistance to radial expanding forces is independent of the shell.

, It is moreover 'among the objects of this invention to provide improvements over prior art lock nuts intended for a generally similar purpose.

With these and other objects in view, the invention consists in the construction, 'arrangement and combination of the various parts of the device whereby the objects contempltaed are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings.

In the drawings: v

Figure 1 is a side elevational view of a lock nut as used.

Figure 2 is a plan view.

Figure 3 is a vertical sectional view of a lock nut embodying this invention as used prior to the application of core-constricting tension.

1; Figure 4 is |a, view similar to Figure 3 showing the parts-after the completion of application of core-constricting tension. Y

Figure 5 is a perspective view of a, core removed from the shell.

Referring more particularly to the drawings, a lock nut chosen as illustrating, without limiting, the invention is generally designated by the numeral I0 and may be used with a bolt I I. Working surfaces or bolted materials as generally designated at I2 comprise, for example, sheets I3 and I4 apertured as at I5 for the insertion of the bolt shank II.

A sheet metal shell IB is preferably polygonal, i. e., hexagonal, in cross-section or as illustrated most clearly in Figure 2 from the top edge 2| to the bottom edge 22 thereof. At the top edge any suitable` means as peening, upsetting, indenting, spinning or the like may be employed for conning a, constrictable `core 23 within the shell. As illustrated, this is done by any number of inwardly turned ears 24 preferably corresponding with the flat sides of the shell.

The bottom 22 of the shell may be rounded as at 25 and fonmed with an inturned annular shoulder 26 defining a bolt-receiving hole 2'I.

The core 23 (cf. Figure 5) may have a hexagonal upper end or half 28 and a lower tapered end or half 29 dening an annular abutment 30. The upper surface 3I of the core, as well as the lower end 32, may be flat, the former having optionally rounded edges 33 for clearing any upset portion of the ears 24 permitting the core freely to engage said ears.

A cbnstricting ring 35 of a preferably hexagonal, cross-sectional conguration makes, like the core a slip t within the interior 36 and bottom 31 of the shell. As illustrated, the ring 35 ishexagonal to conform with the interior conguration of the shell. Another, though less desirable, construction would give the ring 35 and the-inner lower half of the shell a substantially cylindrical form.

An upper portion or half 39 of the ring is tapered, preferably to match the taper of the lower half 23 of the core while the lower end or half- 40 of the ring may be cylindrical. The top 4I of the ring is preferably flat to match the abutment 3D in the core.

As illustrated, the core is split at 42 and a diametrically opposite slot 43 increases its ilexibility. The stock between the bottom of the Slot 43 and the thread 44 of the core should be of a suicient thickness to permit ready compressibilityV of Y the right and left halves 45 and 46 of the core without interfering with the abilityv ofthe core to return, spring-like, to its normal expanded position (Figures 2, 3, and 5). Any other number of slots similar to slot 43 may be provided at spaced intervals around the core as desired. It is also within the spirit of this invention to eliminate all slots similar to 43 leaving only the slot 42.

@iteration In the use of the lock nut herein set forth, the shank I1 of a bolt is applied to the nut in the usual manner through the opening 21 in the' shell and the coincident cylindrical bore in the.'y

ring 35. The thread 44 of the core is meshedv loosely with the threads upon the-bolt while the core is in the upper end of the shell, as illustrated most clearly in Figure 3.

When the head of the bolt firmly engageszthe lower work surfaces I4 and the shell bottoms firmly on the upper work surfaces I3, continuous turning of the nut will draw the core 23 downwardly, the tapered lower end' 29 thereof being drawn down into and compressed' within the tapered upper end 3S of the ring 35 until the shoulder 30 abuts the uppermost edge 4| ofthe ring.

Such abutment establishes the maximum limit of downward movement of the core 23 and, in addition, the core is thus restricted` to its utmost, then occupying a substantially central position within the shell and firmly engaging the bolt to lock the nut thereon. The nut cannot be removed without overcoming the clamping action of the core which is generally relieved, depending upon the angles of taper of the core and ring, by the initial turns made to remove the nut from the bolt. To prevent the ring from following the core during this operation the ringv may be press t into the shell, or otherwise held therein.

Any preferred degree of taper of thev lower portion 29 of the core or the conical portion 39 of the ring may be provided. By wayr of example, it has been found desirable in a three-eighths inch nut to provide a six-degree taper but this size, as well as larger sizes, has been found to operate properlyl with tapers of from three to nine degrees. A class 2-type bolt which has been tapered approximately sixteen degrees in v sizes up to one inch functions properly within The tapered surfaces at 29 and 39 are" preferably identical aithough they may be made to vary from one another for line contact where excessive loads are not encountered.

Nuts of this character may be formed economically by stamping or drawing the shell during the manufacturing process and separately machining or otherwise forming the core and ring. The strength of the nut and of the ringr is independent of the shell and the degree of taper need not be limited due to the strength of theihell, the slighter degrees of taper furnishing a more forcible and slower clamping action than the greater degrees of taper. shell, relieved of radial stresses, merely serves as an envelope to holdr the operating parts inadesired functional relationship. 'I-he conforming surfaces of the core and ring and the preferable slidable fit of the former and' optional slidable. or press t of the latter within the shell minimize distortion of the shell throughapplication of relatively high wrench torque, not otherwise possible in lightweight orl drawn shells of this character.

In view of the permitted predetermination of In any event, the Y core by adjusting the degree and extent of taper through the relative positions of the abutting surfaces 30 and 4I, a maximum tension loading axially is achieved with a minimum load torsionally, and the liability to galling of the threads lof the nut or bolt or the breakage of the bolt to excessive torsional strain, particularly where slight tapersv are used, is:` virtuallyeliminated.

This invention features the provision of a drawn lightweight shell confining a core and ring independently made by any suitable process as by casting or machining. The invention also features a lock nut of great strength and Aadaptability producible atlow unit cost.

AlthoughV the-invention has been herein shown and describedin what is conceived to be the most Y practical and preferred embodiment, it is recogthe.` maximum extent. of clinching: actionxof; the:

nized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details-disclosed herein but is to be accorded the full scope of the claimsl so-as to embrace any and all. equivalent. structures..

Having describedour. inventiomwhat wey claim as new and desire to secure by Letters Patentis:

1. In a free type collet-acting; lock nut. com.- prising an outer sheet metal type shell and an inner constrictable longitudinally split core.: said shell being substantially cup-shaped andhaving hexagonal side walls,.the bottom of. the shell beingformed with. a. central aperture defining an annular bottom shoulder therearound; said core havingan axial. threaded bore, hexagonal. upper sides slidably nested. within the hexagonalv shell and reinforcing said shell against wrench-comf pressive forces, and a-frusto-conical lower portion inset from. the hexagonal sides delning.y an annu. lar abutment between the upper and lower. portions of the corez. the improvement-comprising a steel. reinforcing ringv having a lengthY greater than that of saidfrusto-conical portionanda top annular. shoulder for engagement in the. extreme position of core constriction with saidannular abutment, a. tapered. bore for constrictable reception.Y of the. frusto-conical portion of the core, and. bottom edges nestedv withinthe bottom portion.of the. shell upon. and against. said annular. bottom` shoulder, said ring top shoulder receiving the axialthrust. of the core. and transmittingsaid thrust by meansof said ring directly against said annular. bottomV shoulder, said bottom shoulder. being pinched and held between said ring. and. a work surface. when applied to a bolt under tension.

2. In a free type-collet-actinglock nut comprising. an outer sheet metal type shell and an inner constrictable longitudinally Split core: said shell being substantially cup-shaped and havingA hexagonal. side walls, the bottom ofthe shell being formed with a central aperture defining a bottom shoulder therearound; said core having an axial threaded bore, hexagonal upper sides slidably` nested within the hexagonal shell and reinforcingl said shell against wrench-compressive forces, and a frusto-conical lower portion inset from the hexagonal sides defining an abutmentv between the upper and lower portions of the core and a steel reinforcing ring having a length greater than that of said frusto-conical portion, andi a top shoulder for engagement in the extreme position of core constriction with said abutment, a tapered bore for constrictable reception of the fruSto-conical. portion of the core, and bottom edges positioned within the bottom portion ofthe shell upon and against said bottom shoulder, said ring top shoul.- der receiving. the axial thrust of the core andA transmitting:` said thrust: by means of' saidring directly against said bottom shoulder, said bottom shoulder being pinched and held between REFERENCES CITED The following references are of record in the le of this patent:

6 UNITED STATES PATENTS Number N D e sald rlng and a, Work surface when applied to a 2,048,298 Seagn July Slt 1936 bolt undef tenslon- 2,266,961 Desbrueres Dec. 23, 194i ROBERT C- SHERWOOD 2,361,979 Tarwafr et a1 Nov. 7, 1944 BERTRAND DELERAY MoURoN. 24101730 Gwynn Nw 5 1946 

